#include<iostream>
using namespace std;
#define M 3
#define N 10
float average(float a[M][N], int m, int n) {
	float sum = 0;
	for (int i = 0; i <m; i++)
	{
		for (int t = 0; t < n; t++)
		{
			sum += a[i][t];
		}
	}
	return sum / (m*n);

}
int main() {
	float a[M][N] = {
		1,2,3,4,5,6,7,8,9,0,
		1,2,3,4,5,6,7,8,9,0,
		1,2,3,4,5,6,7,8,9,0,
	};
	float t = average(a,M,N);
	cout << t << endl;

	return 0;
}